Seven New Colletotrichum Species Gleaned from Various Host Plants in Japan

Colletotrichum species are significant plant-pathogenic fungi that affect a wide range of host plants. In this study, a taxonomical investigation of Colletotrichum species isolated from symptomatic plant leaves collected in Japan was conducted using the polyphasic approach combining morphology and phylogeny. Twenty-two isolates were obtained from herbs, ornamentals, vegetables, and fruit trees. Based on multi-locus phylogenetic analyses and morphological characteristics, the examined isolates were identified as 16 species belonging to six species complexes: C. acutatumspecies complex (CASC, n = 5), C. boninense species complex (CBSC, n = 2), C. dematium species complex (CDSC, n = 1), C. dracaenophilum species complex (CDraSC, n = 1), C. gloeosporioides species complex (CGSC, n = 5), and C. destructivum species complex (CVSC, n = 1). Notably, seven of the identified species were recognized as new to science. These results emphasize the importance of continued studies on the fungal biodiversity of Colletotrichum species in Japan.